Hi

I have an xlsx datafile comprising 10 rivers labelled 1..10, 24 observations dated 2000-2023 plus 5 variables (See attached screenshot). I have use File open command specifying it is an xlsx file which it reads and then produces an error message. 

Found 1 valid sheet

I am using Gretll version 2025c

I get the same error message if I specify File, New Data set, Panel data with  n=10 and t=24 and then append the data. 

The full dataset is also appended for information. Advice welcomed as I cannot move forward without getting Gretl to read swhat is a basic XLSX file. I have in earlier versions had no problems loading similararly structured stacked time series for panel data analysis